Often yes, but it depends on whether your program is English-taught or Japanese-taught, and whether you qualify for waivers. For English-medium tracks, Ritsumeikan commonly asks for proof of English ability, but may waive it if your recent education was fully in English (depending on the program and rule set).
Real examples from recipients: Muhammad Hamza Mehdi said, “I took the IELTS and scored 8.0 out of 9.0.” On the other hand, Chhay LIM said, “My scholarship did not require certified English test scores if my previous degree was conducted entirely in English,” though he still had to sit written language exams as required by the scholarship route.
For Japanese-taught programs and daily life, Japanese ability helps a lot. Dinh Khanh An also noted he had “zero knowledge of Japanese” when he applied, so it can be possible to start without Japanese in some cases, but it’s still a practical advantage to learn it.